The visit, which happened last week, is the clearest sign yet that a probe that initially scrutinized Brown’s husband, Benton Cook III, has expanded to include Brown herself.

Story Continued Below

One source said the phone seizure was intended to allow investigators to review text messages on the device.

Sources with knowledge of the investigation tell POLITICO that clerk office employees have received federal subpoenas from the Chicago U.S. attorney’s office.

Sources say one line of inquiry centers on Brown’s relationship with employees, their contributions to her political fund and whether those who donated were rewarded.

A separate subpoena served on Brown and Cook earlier this year asked for documents tied her husband’s halal meat business and the Sankofa Group LLC., a private entity once registered to Brown’s home.

Last year, Cook became a focal point in the gubernatorial campaign after the Chicago Sun-Times revealed that Cook was hired to help supervise $2.1 million in anti-violence grants that were part of then-governor Pat Quinn’s much-maligned Neighborhood Recovery Initiative — despite having a felony conviction for a financial crime.

The U.S. attorney in Springfield at the time pursued an investigation into Cook’s involvement. The FBI and U.S. Attorney’s office in Chicago later took over the probe and are now heading it, sources said.

In 2013, Fox 32 and the Better Government Association reported that a campaign donor gave her husband a parcel for just $1. Brown’s name was later added to paperwork and Sankofa Group ended up on the title. The couple flipped the land, selling it for $100,000. Brown did not disclose the land as a gift or donation on state economic interest forms.

Brown has long been criticized for accepting political money from her underlings, but has denied she pressured them to donate. In 2012, her election opponent, Ald. Ricardo Munoz (22nd), blasted Brown for the practice. She later announced she would no longer take money from employees.

The circuit court clerk’s office is a repository for Cook County court records. Her office has long been criticized for failing to make technological advancements, and she’s been sensitive to them. Brown oversees a massive operation.

“As the official keeper of records for all judicial matters brought into one of the largest unified court systems in the world, the Clerk’s Office serves the 5.2 million people of Cook County, more than 400 judges and maintains offices in Chicago, Skokie, Rolling Meadows, Maywood, Bridgeview and Markham,” she wrote on her web site. “To handle day-to-day responsibilities, the Clerk’s Office has a workforce of approximately 1,916 employees and an annual operating budget of more than $80 million.”

Brown’s office did not respond to a request for comment.

Brown has previously denied wrongdoing by both herself and her husband. On the clerk’s website, her personal motto appears: “All my life, wherever I am and whatever I do, I try to conduct myself in a manner that would be pleasing to my father and mother because I represent the hopes and dreams that they instilled in our family.”